Fix #1, add rate limiting, support new simple api.

python-amazon-simple-product-api moved its product.item
variable to product.parsed_response, handle both.
Use html5lib instead of html.parser.
Add rate limiting using bottlenose MaxQPS and rate limiting
code.
Add a user agent string which fixes amazon throwing 503
for specific pages.
Add test for #1.
Skip some tests, amazon are moving more and more into iframes.
Fuck amazon, seriously, fuck amazon.
Bump version